写点什么

Android UI - 实现广告 Banner 轮播效果,Android 大厂 74 道高级面试合集

发布于: 2021 年 11 月 08 日

android:textSize="12sp" />


<TextView


android:id="@+id/tv_topic"


android:layout_width="wrap_content"


android:layout_height="wrap_content"


android:layout_marginLeft="10dp"


android:layout_toRightOf="@+id/tv_topic_from"


android:text="“我想知道令狐安和令计划有什么关系?”"


android:textColor="@color/white"


android:textSize="12sp" />


</RelativeLayout>


</RelativeLayout>


<LinearLayout


android:layout_width="wrap_content"


android:layout_height="wrap_content"


android:layout_marginTop="10dip"


android:layout_gravity="bottom|center_horizontal"


android:layout_marginBottom="10dp"


android:gravity="center" >


<View


android:id="@+id/v_dot0"


style="@style/dot_style"


android:background="@drawable/dot_focused"


android:visibility="invisible" />


<View


android:id="@+id/v_dot1"


style="@style/dot_style"


android:visibility="invisible"/>


<View


android:id="@+id/v_dot2"


style="@style/dot_style"


android:visibility="invisible"/>


<View


android:id="@+id/v_dot3"


style="@style/dot_style"


android:visibility="invisible"/>


<View


android:id="@+id/v_dot4"


style="@style/dot_style"


android:visibility="invisible" />


</LinearLayout>


</FrameLayout>


</LinearLayout>


一个 ViewPager,下面五个指示点,注意每个点都有同样的样式,我们在 style.xml 中定义样式:


/BannerAutoScrollDemo/res/values/styles.xml


<style name="dot_style">


<item name="android:layout_width">5dip</item>


<item name="android:layout_height">5dip</item>


<item name="android:background">@drawable/dot_normal</item>


<item name="android:layout_marginLeft">1.5dip</item>


<item name="android:layout_marginRight">1.5dip</item>


</style>

定义圆点图形资源

/BannerAutoScrollDemo/res/drawable/dot_normal.xml


<?xml version="1.0" encoding="utf-8"?>


<shape xmlns:android="http://schemas.android.com/apk/res/android"


android:shape="oval" >


<solid android:color="#33000000" />


<corners android:radius="5dip" />


</shape>


/BannerAutoScrollDemo/res/drawable/dot_focused.xml


<?xml version="1.0" encoding="utf-8"?>


<shape xmlns:android="http://schemas.android.com/apk/res/android"


android:shape="oval" >


<solid android:color="#aaFFFFFF" />


<corners android:radius="5dip" />


</shape>

定义广告实体

/BannerAutoScrollDemo/src/com/xiaowu/banner/demo/AdDomain.java


package com.xiaowu.banner.demo;


/**


  • 广告实体

  • @author wwj_748


*/


public class AdDomain {


private String id; // 广告 id


private String date; // 日期


private String title; // 标题


private String topicFrom; //选题来自


private String topic; // 选题


private String imgUrl; // 图片 url


private boolean isAd; // 是否为广告


private String startTime; // 广告开始时间


private String endTime; // 广告结束时间


private String targetUrl; // 目标 url


private int width; // 宽


private int height; // 高


private boolean available; // 是否可用


public String getId() {


return id;


}


public void setId(String id) {


this.id = id;


}


public String getTitle() {


return title;


}


public void setTitle(String title) {


this.title = title;


}


public String getImgUrl() {


return imgUrl;


}


public void setImgUrl(String imgUrl) {


this.imgUrl = imgUrl;


}


public boolean isAd() {


return isAd;


}


public void setAd(boolean isAd) {


this.isAd = isAd;


}


public String getDate() {


return date;


}


public void setDate(String date) {


this.date = date;


}


public String getTopic() {


return topic;


}


public void setTopic(String topic) {


this.topic = topic;


}


public String getTopicFrom() {


return topicFrom;


}


public void setTopicFrom(String topicFrom) {


this.topicFrom = topicFrom;


}


public String getStartTime() {


return startTime;


}


public void setStartTime(String startTime) {


this.startTime = startTime;


}


public String getEndTime() {


return endTime;


}


public void setEndTime(String endTime) {


this.endTime = endTime;


}


public String getTargetUrl() {


return targetUrl;


}


public void setTargetUrl(String targetUrl) {


this.targetUrl = targetUrl;


}


public int getWidth() {


return width;


}


public void setWidth(int width) {


this.width = width;


}


public int getHeight() {


return height;


}


public void setHeight(int height) {


this.height = height;


}


public boolean isAvailable() {


return available;


}


public void setAvailable(boolean available) {


this.available = available;


}


}

实现切换逻辑

1. 定时切换


2. 切换图片


3. 切换标题


4. 切换指示器


定时切换用到一个类:ScheduledExecutorService


作用是定时执行任务,我们这里要做的定时任务是,2 秒执行一次图片切换


private void startAd() {


scheduledExecutorService = Executors.newSingleThreadScheduledExecutor();


// 当 Activity 显示出来后,每两秒切换一次图片显示


scheduledExecutorService.scheduleAtFixedRate(new ScrollTask(), 1, 2,


TimeUnit.SECONDS);


}


定义子线程


private class ScrollTask implements Runnable {


@Override


public void run() {


synchronized (adViewPager) {


currentItem = (currentItem + 1) % imageViews.size();


handler.obtainMessage().sendToTarget();


}


}


}


通过 handle 来通知 ViewPager 进行视图切换


private Handler handler = new Handler() {


public void handleMessage(android.os.Message msg) {


adViewPager.setCurrentItem(currentItem);


};


};


我们提供模拟数据来进行测试


/**


  • 轮播广播模拟数据

  • @return


*/


public static List<AdDomain> getBannerAd() {


List<AdDomain> adList = new ArrayList<AdDomain>();


AdDomain adDomain = new AdDomain();


adDomain.setId("108078");


adDomain.setDate("3 月 4 日");


adDomain.setTitle("我和令计划只是同姓");


adDomain.setTopicFrom("阿宅");


adDomain.setTopic("我想知道令狐安和令计划有什么关系?");


adDomain.setImgUrl("http://g.hiphotos.baidu.com/image/w%3D310/sign=bb99d6add2c8a786be2a4c0f5708c9c7/d50735fae6cd7b8900d74cd40c2442a7d9330e29.jpg");


adDomain.setAd(false);


adList.add(adDomain);


AdDomain adDomain2 = new AdDomain();


adDomain2.setId("108078");


adDomain2.setDate("3 月 5 日");


adDomain2.setTitle("我和令计划只是同姓");


adDomain2.setTopicFrom("小巫");


adDomain2.setTopic("“我想知道令狐安和令计划有什么关系?”");


adDomain2


.setImgUrl("http://g.hiphotos.baidu.com/image/w%3D310/sign=7cbcd7da78f40ad115e4c1e2672e1151/eaf81a4c510fd9f9a1edb58b262dd42a2934a45e.jpg");


adDomain2.setAd(false);


adList.add(adDomain2);


AdDomain adDomain3 = new AdDomain();


adDomain3.setId("108078");


adDomain3.setDate("3 月 6 日");


adDomain3.setTitle("我和令计划只是同姓");


adDomain3.setTopicFrom("旭东");


adDomain3.setTopic("“我想知道令狐安和令计划有什么关系?”");


adDomain3


.setImgUrl("http://e.hiphotos.baidu.com/image/w%3D310/sign=392ce7f779899e51788e3c1572a6d990/8718367adab44aed22a58aeeb11c8701a08bfbd4.jpg");


adDomain3.setAd(false);


adList.add(adDomain3);


AdDomain adDomain4 = new AdDomain();


adDomain4.setId("108078");


adDomain4.setDate("3 月 7 日");


adDomain4.setTitle("我和令计划只是同姓");


adDomain4.setTopicFrom("小软");


adDomain4.setTopic("“我想知道令狐安和令计划有什么关系?”");


adDomain4


.setImgUrl("http://d.hiphotos.baidu.com/image/w%3D310/sign=54884c82b78f8c54e3d3c32e0a282dee/a686c9177f3e670932e4cf9338c79f3df9dc55f2.jpg");


adDomain4.setAd(false);


adList.add(adDomain4);


AdDomain adDomain5 = new AdDomain();


adDomain5.setId("108078");


adDomain5.setDate("3 月 8 日");


adDomain5.setTitle("我和令计划只是同姓");


adDomain5.setTopicFrom("大熊");


adDomain5.setTopic("“我想知道令狐安和令计划有什么关系?”");


adDomain5


.setImgUrl("http://e.hiphotos.baidu.com/image/w%3D310/sign=66270b4fe8c4b7453494b117fffd1e78/0bd162d9f2d3572c7dad11ba8913632762d0c30d.jpg");


adDomain5.setAd(true); // 代表是广告


adList.add(adDomain5);


return adList;


}


ViewPager 逻辑处理


1. 填充数据(自定义 Adapter)


2. 设置页面切换监听事件


3. 在自定义 adapter 中的 instantiateItem 方法设置 ViewPager 点击事件


这里我们的图片是从网上下载的,用到了 universal-image-loader-1.8.6-with-sources.jar 这个类库,可以实现异步加载图片,具体使用查看代码。


最后给出完整代码:


/BannerAutoScrollDemo/src/com/xiaowu/banner/demo/MainActivity.java


package com.xiaowu.banner.demo;


import java.io.File;


import java.util.ArrayList;


import java.util.List;


import java.util.concurrent.Executors;


import java.util.concurrent.ScheduledExecutorService;


import java.util.concurrent.TimeUnit;


import android.app.Activity;


import android.graphics.Bitmap;


import android.os.Bundle;


import android.os.Handler;


import android.os.Parcelable;


import android.support.v4.view.PagerAdapter;


import android.support.v4.view.ViewPager;


import android.support.v4.view.ViewPager.OnPageChangeListener;


import android.view.View;


import android.view.View.OnClickListener;


import android.view.ViewGroup;


import android.widget.ImageView;


import android.widget.ImageView.ScaleType;


import android.widget.TextView;


import com.nostra13.universalimageloader.cache.disc.impl.UnlimitedDiscCache;


import com.nostra13.universalimageloader.cache.memory.impl.LruMemoryCache;


import com.nostra13.universalimageloader.core.DisplayImageOptions;


import com.nostra13.universalimageloader.core.ImageLoader;


import com.nostra13.universalimageloader.core.ImageLoaderConfiguration;


import com.nostra13.universalimageloader.core.assist.ImageScaleType;


import com.nostra13.universalimageloader.core.assist.QueueProcessingType;


public class MainActivity extends Activity {


public static String IMAGE_CACHE_PATH = "imageloader/Cache"; // 图片缓存路径


private ViewPager adViewPager;


private List<ImageView> imageViews;// 滑动的图片集合


private List<View> dots; // 图片标题正文的那些点


private List<View> dotList;


private TextView tv_date;


private TextView tv_title;


private TextView tv_topic_from;


private TextView tv_topic;


private int currentItem = 0; // 当前图片的索引号


// 定义的五个指示点


private View dot0;


private View dot1;


private View dot2;


private View dot3;


private View dot4;


// 定时任务


private ScheduledExecutorService scheduledExecutorService;


// 异步加载图片


private ImageLoader mImageLoader;


private DisplayImageOptions options;


// 轮播 banner 的数据


private List<AdDomain> adList;


private Handler handler = new Handler() {


public void handleMessage(android.os.Message msg) {


adViewPager.setCurrentItem(currentItem);


};


};


@Override


protected void onCreate(Bundle savedInstanceState) {


super.onCreate(savedInstanceState);


setContentView(R.layout.activity_main);


// 使用 ImageLoader 之前初始化


initImageLoader();


// 获取图片加载实例


mImageLoader = ImageLoader.getInstance();


options = new DisplayImageOptions.Builder()


.showStubImage(R.drawable.top_banner_android)


.showImageForEmptyUri(R.drawable.top_banner_android)


.showImageOnFail(R.drawable.top_banner_android)


.cacheInMemory(true).cacheOnDisc(true)


.bitmapConfig(Bitmap.Config.RGB_565)


.imageScaleType(ImageScaleType.EXACTLY).build();


initAdData();


startAd();


}


/**


  • 初始化 ImageLoader


*/


private void initImageLoader() {


File cacheDir = com.nostra13.universalimageloader.utils.StorageUtils


.getOwnCacheDirectory(getApplicationContext(),


IMAGE_CACHE_PATH);


DisplayImageOptions defaultOptions = new DisplayImageOptions.Builder()


.cacheInMemory(true).cacheOnDisc(true).build();


ImageLoaderConfiguration config = new ImageLoaderConfiguration.Builder(


this).defaultDisplayImageOptions(defaultOptions)


.memoryCache(new LruMemoryCache(12 * 1024 * 1024))


.memoryCacheSize(12 * 1024 * 1024)


.discCacheSize(32 * 1024 * 1024).discCacheFileCount(100)


.discCache(new UnlimitedDiscCache(cacheDir))


.threadPriority(Thread.NORM_PRIORITY - 2)


.tasksProcessingOrder(QueueProcessingType.LIFO).build();


ImageLoader.getInstance().init(config);


}


/**


  • 初始化广告数据


*/


private void initAdData() {


// 广告数据


adList = getBannerAd();


imageViews = new ArrayList<ImageView>();


// 点


dots = new ArrayList<View>();


dotList = new ArrayList<View>();


dot0 = findViewById(R.id.v_dot0);


dot1 = findViewById(R.id.v_dot1);


dot2 = findViewById(R.id.v_dot2);


dot3 = findViewById(R.id.v_dot3);


dot4 = findViewById(R.id.v_dot4);


dots.add(dot0);


dots.add(dot1);


dots.add(dot2);


dots.add(dot3);


dots.add(dot4);


tv_date = (TextView) findViewById(R.id.tv_date);


tv_title = (TextView) findViewById(R.id.tv_title);


tv_topic_from = (TextView) findViewById(R.id.tv_topic_from);


tv_topic = (TextView) findViewById(R.id.tv_topic);


adViewPager = (ViewPager) findViewById(R.id.vp);


adVie


《Android学习笔记总结+最新移动架构视频+大厂安卓面试真题+项目实战源码讲义》
浏览器打开:qq.cn.hn/FTe 免费领取
复制代码


wPager.setAdapter(new MyAdapter());// 设置填充 ViewPager 页面的适配器


// 设置一个监听器,当 ViewPager 中的页面改变时调用


adViewPager.setOnPageChangeListener(new MyPageChangeListener());


addDynamicView();


}


private void addDynamicView() {


// 动态添加图片和下面指示的圆点


// 初始化图片资源


for (int i = 0; i < adList.size(); i++) {


ImageView imageView = new ImageView(this);


// 异步加载图片


mImageLoader.displayImage(adList.get(i).getImgUrl(), imageView,


options);


imageView.setScaleType(ScaleType.CENTER_CROP);


imageViews.add(imageView);


dots.get(i).setVisibility(View.VISIBLE);


dotList.add(dots.get(i));


}


}


@Override


protected void onResume() {


super.onResume();


}


private void startAd() {


scheduledExecutorService = Executors.newSingleThreadScheduledExecutor();


// 当 Activity 显示出来后,每两秒切换一次图片显示


scheduledExecutorService.scheduleAtFixedRate(new ScrollTask(), 1, 2,


TimeUnit.SECONDS);


}


private class ScrollTask implements Runnable {


@Override


public void run() {


synchronized (adViewPager) {


currentItem = (currentItem + 1) % imageViews.size();


handler.obtainMessage().sendToTarget();


}


}


}


@Override


protected void onStop() {


super.onStop();


// 当 Activity 不可见的时候停止切换


scheduledExecutorService.shutdown();


}


private class MyPageChangeListener implements OnPageChangeListener {


private int oldPosition = 0;


@Override


public void onPageScrollStateChanged(int arg0) {

评论

发布
暂无评论
Android UI - 实现广告Banner轮播效果,Android大厂74道高级面试合集